J/AJ/168/116ivo://CDS.VizieR/J/AJ/168/116doi:10.26093/cds/vizier.51680116CDSRadzom B.T.Dong J.Rice M.Wang X.-Y.Yee S.W.Fairnington T.R.,Petrovich C.Wang S.2025-05-21T20:12:37Z2025-02-06T14:27:59ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frradial-velocityexoplanetsvisible-astronomyspectroscopyDespite decades of effort, the mechanisms by which the spin axis of a star and the orbital axes of its planets become misaligned remain elusive. In particular, it is of great interest whether the large spin-orbit misalignments observed are driven primarily by high-eccentricity migration-expected to have occurred for short-period, isolated planets-or reflect a more universal process that operates across systems with a variety of present-day architectures. Compact multiplanet systems offer a unique opportunity to differentiate between these competing hypotheses, as their tightly packed configurations preclude violent dynamical histories, including high-eccentricity migration, allowing them to trace the primordial disk plane. In this context, we report measurements of the sky-projected stellar obliquity ({lambda}) via the Rossiter-McLaughlin effect for two sub-Saturns in multiple- transiting systems: TOI-5126 b ({lambda}=1+/-48{deg}) and TOI-5398 b ({lambda}=-8.1_-6.3_^+5.3^{deg}). Both are spin-orbit aligned, joining a fast-growing group of just three other compact sub-Saturn systems, all of which exhibit spin-orbit alignment. In aggregate with archival data, our results strongly suggest that sub-Saturn systems are primordially aligned and become misaligned largely in the postdisk phase, as appears to be the case increasingly for other exoplanet populations.2024AJ....168..116Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/116CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/328 : AllWISE Data Release (Cutri+ 2013)IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)J/ApJ/723/L223 : Radial velocities of HAT-P-11 (Winn+, 2010)J/ApJ/757/18 : RVs for 16 hot Jupiter host stars (Albrecht+, 2012)J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)J/ApJ/780/159 : Rot-mass-age relationship of old field stars (Epstein+, 2014)J/ApJ/828/46 : ALMA survey of Lupus protopl. disks. I. (Ansdell+, 2016)J/ApJ/831/125 : ALMA 887um obs. of ChaI star-forming region (Pascucci+, 2016)J/A+A/608/A135 : Sodium detection in WASP-69b atm. (Casasayas-Barris+, 2017)J/ApJ/834/17 : Mass & radius of planets, moons, low mass stars (Chen+, 2017)J/ApJ/860/109 : Keck HIRES obs. of subgiants (retired A stars) (Ghezzi+, 2018)J/A+A/613/A41 : 5 exoplanet light and RV curves (Mancini+, 2018)J/AJ/160/192 : Photometry and RVs of K2-25b with HPF (Stefansson+, 2020)J/other/ExA/51.109 : Transit KELT-11b observed by CHEOPS (Benz+, 2021)J/A+A/645/A106 : Atomic data for the Gaia-ESO Survey (Heiter+, 2021)J/AJ/162/263 : TESS nearby planetary companions to hot Jupiters (Hord+, 2021)J/AJ/161/68 : Obliquities of hot Kepler hosting stars (Louden+, 2021)J/AJ/161/119 : The TESS-Keck survey. IV. Rvel for WASP-107 (Rubenzahl+, 2021)J/AJ/164/26 : Hot Jupiters isochrones & stellar modeling (Hamer+, 2022)J/AJ/163/247 : HIRES, PEPSI & TRES RVs of V1298 Tau (Johnson+, 2022)J/AJ/164/104 : NEID and HIRES radial velocity of TOI-1478 (Rice+, 2022)J/ApJ/926/L8 : Spectroscopic and transit obs. of WASP-148 (Wang+, 2022)J/AJ/165/33 : HIRES TOI-1136s planets & planet b RVels (Dai+, 2023)J/AJ/166/266 : Photometry obtained for TOI-2202b (Rice+, 2023)J/AJ/167/175 : Radial velocity and photometry of TOI-677 (Hu+, 2024)J/A+A/682/A129 : TOI-5398 spectroscopic time-series (Mantovan+, 2024)J/A+A/684/L17 : TOI-5398 radial velocity curve (Mantovan+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/168/116https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/168/116http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/168/116https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/168/116https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/168/116http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/168/116GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/168/116/fig1NEID radial velocities of TOI-5126 and TOI-5398recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentifier ("TOI 5126" or "TOI 5398")meta.id;meta.maincharTransitIn or out of transit (1)meta.notecharBJDBarycentric Julian date of mid-pointdtime.epochdoubleRVel[-9.65/12.42] Radial velocity (2)km/sspect.dopplerVelocfloate_RVel[0.003/0.02] Uncertainty in RVelkm/sstat.error;spect.dopplerVelocfloatb_BJDStart time of RVel observationdstat.min;time.epochdoubleB_BJDEnd time of RVel observationdstat.max;time.epochdouble